Triple Threat: MIT Chip Harvests Energy from Heat, Light and Movement
© Christine Daniloff
File this under one of the coolest things I've read about in a long time: a chip design that can continually and almost simultaneously draw energy from three different sources. The chip is designed to harness thermoelectric, photovoltaic and piezoelectric energy and either run directly off of that energy or off of onboard energy storage. The chip could be used to power remote environmental sensors or gauges and even biomedical devices.
Previous research out of MIT’s Department of Electrical Engineering and Computer Science has lead to computer and wireless communications chips that could run off of ambient heat, light or vibrations, but through a breakthrough energy-combining circuit design, this new chip can run off all three at once.
MIT News reports, "So far, most efforts to harness multiple energy sources have simply switched among them, taking advantage of whichever one is generating the most energy at a given moment, Bandyopadhyay says, but that can waste the energy being delivered by the other sources...The approach combines energy from multiple sources by switching rapidly between them."
Harnessing energy from all three sources at once optimizes the ability for devices to be powered by these ambient sources of power, which tend to be incremental or inconsistent. For example, a remote sensor monitoring stresses to a bridge could capture energy from the vibration of traffic, sunlight and temperature changes all at once or as any one or two of those energy sources are available, instead of choosing just one at a time.
Another boost to efficiency is the ability for the system to power a sensor directly instead of the energy going first to a storage device and then to power the device. This control system can do both, which leads to less wasted energy.
As remote sensors become more widely used and important, their ability to power themselves is crucial. This design could make them totally self-sufficient and allow them to do more things.
David Freeman, chief technologist at Texas Instruments where low-power microcontrollers and wireless transceivers have started to be developed to run off of ambient sources, says this breakthrough will push wireless sensor technology forward. “With innovations like these that combine multiple sources of energy, these systems can now start to increase functionality," he says.